AU2019279208B2

AU2019279208B2 - Composite material and bioimplant

Info

Publication number: AU2019279208B2
Application number: AU2019279208A
Authority: AU
Inventors: Masayuki Kyomoto; Kenichi SAIGA; Kenichi Watanabe
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2018-06-01
Filing date: 2019-05-30
Publication date: 2022-01-27
Anticipated expiration: 2039-05-30
Also published as: JPWO2019230871A1; CN112188903A; EP3804768A9; AU2019279208A1; JP2024028859A; US20210196862A1; JP7155259B2; JP7400049B2; JP2023015032A; EP3804768A1; WO2019230871A1; EP3804768A4

Abstract

A composite material according to one embodiment has a crystal phase of a titanium fluoride and a metal crystal phase of titanium. The crystal phase of titanium fluoride is present in a first region located away from the surface in the depth direction.

Description

DESCRIPTION COMPOSITE MATERIAL AND BIOIMPLANT TECHNICAL FIELD

[0001]

The present disclosure relates to a composite

material and a bioimplant.

BACKGROUND ART

[0002]

A metal material whose surface is subjected to

fluorine ion implantation has been known (for example,

refer to Patent Document 1 and Non-patent Document 1).

RELATED ART DOCUMENTS PATENT DOCUMENT

[0003]

Patent Document 1: Japanese Patent No. 4568396

NON-PATENT DOCUMENT

[00041

Non-patent Document 1: M. Yoshinari, Y. Oda, T.

Kato, K. Okuda, "Influence of surface modifications to

titanium on antibacterial activity in vitro,"

Biomaterials, 2001, 22, p. 2043-2048

SUMMARY

[0005]

A composite material in one of embodiments includes

a crystal phase of titanium fluoride and a metal crystal phase of titanium. The crystal phase of the titanium fluoride is present in a first region located away from a surface in a depth direction.

[0006]

A bioimplant in one of embodiments includes the

composite material in one of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]

FIG. 1 is a schematic diagram illustrating a

composite material in one of embodiments;

FIG. 2 is one embodiment of a bioimplant in one of

embodiments;

FIG. 3 is a graph illustrating fluorine

concentration measurement results in Examples; and

FIG. 4 is a graph illustrating hardness measurement

results in Examples and Comparative Example.

EMBODIMENTS

[00081

A composite material in one of embodiments is

described in detail below with reference to the drawings.

For the sake of description, the drawings referred to in

the following illustrate, in simplified form, only main

configurations necessary for describing the embodiments.

The composite material in the embodiment is therefore

capable of including any arbitrary configuration not

illustrated in the drawings referred to. Dimensions of the configurations in the drawings faithfully represent neither dimensions of actual configurations nor dimensional ratios of these configurations. These points are also true for a bioimplant described later.

[00091

FIG. 1 is a schematic diagram illustrating the

composite material in the embodiment. A cross section of

a part including a surface of the composite material is

enlargedly illustrated in FIG. 1.

[0010]

The composite material 1 includes titanium (Ti) and

fluorine (F) and includes a crystal phase 2 of titanium

fluoride (hereinafter also referred to as "the crystal

phase 2") and a metal crystal phase 3 of titanium

(hereinafter also referred to as "the metal crystal phase

3"). The titanium fluoride that is a compound of

titanium and fluorine is present in a crystal state in

the crystal phase 2. The titanium is present in a state

of crystal formed by metallic bonding in the metal

crystal phase 3.

[0011]

The composite material 1 includes fluorine and the

crystal phase 2 as described above. Therefore, it

becomes possible to offer antibacterial activity owing to

the fluorine. Because the composite material 1 has high

hardness, it becomes possible to offer excellent wear

resistance or the like. The reason why the composite material 1 has the high hardness seems to be as follows.

[0012]

The bonding between titanium and fluorine in the

titanium fluoride is covalent bonding. The crystal phase

2 therefore serves as an obstacle to dislocation for

moving the metal crystal phase 3. Accordingly, if the

composite material 1 includes the crystal phase 2, an

amount of energy necessary for dislocation movement

becomes larger, thus leading to enhanced hardness of the

composite material 1. A ratio of the crystal phase 2

tends to increase with increasing a fluorine

concentration in the composite material 1.

[00131

Examples of the titanium fluoride include TiF

(titanium monofluoride), TiF2 (titanium difluoride), TiF3

(titanium trifluoride), TiF4 (titanium tetrafluoride),

TiOF (titanium oxyfluoride), TiOF2 (titanium

oxydifluoride) and F-TiO2 (fluorine doped titanium oxide).

The titanium fluoride may be TiOF2. The crystal phase 2

may include Ti-F-Ti bonding (covalent bonding).

[0014]

As a method for measuring a crystal structure,

there are, for example, Transmission Electron Microscope

(hereinafter also referred to as "TEM"), X-ray

Diffraction (hereinafter also referred to as "XRD") and

X-ray Photoelectron Spectroscopy (hereinafter also

referred to as "XPS").

[0015]

The composite material 1 may include a region

(first region) 12 which includes a surface 11 of the

composite material 1 and has a predetermined thickness in

a depth direction from the surface 11. The first region

12 is a composite phase of titanium and fluorine. A

fluorine concentration of the first region 12 may be 1

ppm or more.

[00161

A thickness T of the first region 12 is, for

example, 30-800 nm. If a numerical value range is

indicated using "-", numerical values of a lower limit

and an upper limit are included unless otherwise noted.

For example, a numerical value range of 30-800 nm denotes

that the lower limit is 30 nm or more and the upper limit

is 800 nm or less.

[0017]

The crystal phase 2 may be located in the first

region 12. If satisfying this configuration, the crystal

phase 2 is located in the vicinity of the surface 11.

This contributes to enhancing antibacterial activity

owing to the fluorine in the titanium fluoride and also

increasing hardness of the surface 11 and neighborhoods

thereof.

[0018]

The crystal phase 2 may be located in a region with

a depth range of 20-200 nm from the surface 11. The depth may be determined on the basis of the surface 11.

[0019]

The metal crystal phase 3 may include a first phase

31 containing fluorine (fluorine-containing phase). In

other words, the metal crystal phase 3 may include the

first phase 31 including fluorine in a crystal lattice of

titanium. The fluorine may be introduced as an

interstitial element into the crystal lattice of titanium

in the first phase 31. If the metal crystal phase 3

includes the first phase 31, the hardness of the

composite material 1 can be further enhanced. The reason

for this seems to be as follows.

[00201

A fluorine atom enters a space in the crystal

lattice of titanium formed by metallic bonding in the

first phase 31. The crystal of titanium is therefore

subjected to lattice distortion according to a size of

the fluorine atom thus entered. Deformation of the

crystal lattice of titanium is caused by dislocation

movement that is a defect of the crystal lattice. When

the titanium crystal lattice strain occurred by fluorine

doping, dislocation mobility is decreased and hardness of

the composite material 1 is increased. Hence, with the

metal crystal phase 3 including the first phase 31, the

first phase 31 besides the crystal phase 2 also

contributes to the hardness of the composite material 1,

thereby further enhancing the hardness of the composite material 1. A ratio of the first phase 31 tends to increase with decreasing the fluorine concentration in the composite material 1.

[0021]

The first phase 31 may be located in the first

region 12. If satisfying this configuration, the

hardness of the surface 11 and neighborhoods thereof can

be enhanced because the first phase 31 is located in the

vicinity of the surface 11. The first region 12 in which

the first phase 31 is located is identical with the first

region 12 in which the crystal phase 2 is located. This

is also true for the first region 12 in which a second

phase 32 described later is located, the first region 12

at which a maximum value of fluorine concentration is

located, and the first region 12 at which a maximum value

of hardness is located. That is, the first regions 12 in

the description of the individual configurations are

identical to each other.

[0022]

The metal crystal phase 3 may further include a

second phase 32 including no fluorine (non-fluorine

containing phase) located more inside than the first

phase 31. If satisfying this configuration, a region

including the first phase 31, which is located closer to

the surface 11 than the second phase 32, is less

susceptible to damage. Specifically, because the second

phase 32 includes no fluorine, the second phase 32 has higher toughness than the first phase 31. Accordingly, upon impact on the surface 11, the impact can be relaxed by the second phase 32 having relatively high toughness.

Consequently, the region including the first phase 31,

which is located closer to the surface 11 than the second

phase 32, becomes less susceptible to damage.

[0023]

The phrase that "the second phase 32 is located

more inside than the first phase 31" denotes that the

second phase 32 is located more away from the surface 11

than the first phase 31. The term "inside" denotes being

located inside the composite material 1 relative to the

surface 11. In other words, the term "inside" denotes a

depth increasing direction in the composite material 1.

The term "including no fluorine" denotes a state of

including substantially no fluorine and being

substantially free from influence of fluorine.

Specifically, if the fluorine concentration is less than

1 ppm, a determination may be made that it is free from

fluorine.

[0024]

The second phase 32 may be located more inside than

the first region 12. If satisfying this configuration,

the first region 12 located closer to the surface 11 than

the second phase 32 is less susceptible to damage because

the second phase 32 has relatively high toughness.

[00251

The composite material 1 may further include a

region (second region) 13 located more inside than the

first region 12. The second region may the region

including titanium but not including fluorine. The

second phase 32 may be located in the second region. The

second region 13 may be in contact with the first region

12. That is, the first region 12 and the second region

13 may be continuous regions in the composite material 1.

[0026]

The metal crystal phase 3 may include, for example,

a titanium-based metal. Examples of the titanium-based

metal include pure titanium and titanium alloys.

Examples of the pure titanium include industrial pure

titanium, such as C.P. two types titanium whose base

phase is titanium. The titanium alloys are alloys whose

base phase is titanium. Examples thereof include Ti

6Al(aluminum)-4V(vanadium), Ti-15Mo(molybdenum)

5Zr(zirconium)-3Al, Ti-Nb(niobium), Ti-6Al-7Nb, Ti-6Al

2Nb-lTa(tantalum), Ti-30Zr-Mo, Ni(nickel)-Ti, Ti-3Al-2.5V,

Ti-l0V-2Fe(iron)-3Al and Ti-15V-3Cr(chrome)-3Al-3Sn(tin).

[0027)

The composite material 1 may further include an

amorphous phase 4 including titanium and fluorine. If

satisfying this configuration, the composite material 1

is less susceptible to damage because the amorphous phase

4 has high toughness.

[0028]

The amorphous phase 4 may be located in the first

region 12. If satisfying this configuration, the first

region 12 becomes less susceptible to damage because the

amorphous phase 4 has the high toughness.

[0029]

The composite material 1 may further include a

mixed phase 5 including the amorphous phase 4, the

crystal phase 2 and the metal crystal phase 3 (the first

phase 31). The mixed phase 5 is located in the first

region 12 in one of the embodiments. The amorphous

phases 4, the crystal phases 2 and the metal crystal

phases 3 are mixed in the mixed phase 5. Although

material characteristics of the individual phases are

different from each other, the material characteristics

of the composite material 1 in the first region 12 become

characteristics according to a ratio of the individual

phases. Specifically, their respective material

characteristics become those obtained by averaging the

material characteristics of the included individual

phases, or alternatively, become characteristics close to

average characteristics. That is, the composite material

1 includes the individual phases as the mixed phase 5,

making it possible to reduce parts different in material

characteristics in the first region. With the composite

material 1 including the mixed phase 5, it is possible to

reduce the probability that a material partially

separates from the first region 12. This leads to improved stability of the composite material 1.

[0030]

The fluorine concentration in the composite

material 1 may reach a maximum value at a portion located

more inside than the surface 11 (refer to FIG. 3). If

satisfying this configuration, in a situation where the

surface 11 is newly exposed due to wear or the like, the

surface 11 having a relatively high fluorine

concentration tends to be exposed. This facilitates to

offer antibacterial activity over a long period of time.

[0031]

The fluorine concentration may increase to a

maximum value as going from the surface 11 toward the

inside (refer to FIG. 3). In other words, the fluorine

concentration may increase to the maximum value with

increasing depth. If satisfying this configuration, in

the situation where the surface 11 is newly exposed due

to wear or the like, the surface 11 having the relatively

high fluorine concentration tends to be exposed. This

facilitates to offer antibacterial activity over the long

period of time. A period of time during which the

composite material 1 offers the antibacterial activity

can be controlled by controlling a distribution of the

fluorine concentration.

[00321

The maximum value of the fluorine concentration may

be located in the first region 12. If satisfying this configuration, the maximum value of the fluorine concentration is located in the vicinity of the surface

11, thus enhancing the antibacterial activity.

[0033]

The maximum value of the fluorine concentration may

be located closer to a side of the surface 11 than a

midportion 12a in a thickness direction A of the first

region 12 (refer to FIGs. 1 and 3). If satisfying this

configuration, the maximum value of the fluorine

concentration is located in the vicinity of the surface

11, thus leading to the enhanced antibacterial activity.

[00341

A concentration in the fluorine concentration is an

atomic concentration. The fluorine concentration in one

of the embodiments is the number of fluorine atoms per

unit volume relative to a sum of an ideal atomic number

of titanium atoms per unit volume and the number of

fluorine atoms. Examples of a method for measuring a

fluorine concentration include Secondary Ion Mass

Spectrometry (hereinafter also referred to as "SIMS") and

XPS. The SIMS is suitable in cases where the fluorine

concentration is relatively low. The XPS is suitable in

cases where the fluorine concentration is relatively high.

[0035]

The maximum value of fluorine concentration is, for

example, 10-80 atom%. A fluorine concentration in a

region from the surface 11 to less than 5 nm depth is, for example, 0.5-20 atom%. A fluorine concentration in a region with a depth range of not less than 5 nm but less than 20 nm is, for example, 2-30 atom%. A fluorine concentration in a region with a depth range of not less than 20 nm but less than 50 nm is, for example, 5-80 atom%. A fluorine concentration in a region with a depth range of not less than 50 nm but not more than 100 nm is, for example, 2-80 atom%.

[0036]

The hardness of the composite material 1 may reach

a maximum value at a portion located more inside than the

surface 11 (refer to FIG. 4). If satisfying this

configuration, in the situation where the surface 11 is

newly exposed due to wear or the like, the surface 11

having relatively high hardness tends to be exposed.

This enhances the possibility that the surface 11 has the

high hardness over a long period of time. The surface 11

in the description of the hardness is identical to the

surface 11 in the above description of the fluorine

concentration.

[0037]

The hardness may increase to a maximum value as

going from the surface 11 toward the inside (refer to FIG.

4). In other words, the hardness may increase to the

maximum value with increasing depth. If satisfying this

configuration, in the situation where the surface 11 is

newly exposed due to wear or the like, the surface 11 having the relatively high hardness tends to be exposed.

This leads to the high hardness of the surface 11 over a

long period of time.

[00381

Alternatively, the hardness may increase to a

maximum value as going from the surface 11 toward the

inside, and thereafter may decrease as going more inside

(refer to FIG. 4). In other words, the composite

material 1 may be configured so that the hardness changes

moderately in the inside. With this configuration, a

local stress is less likely to occur than a configuration

that hardness inside the composite material 1 changes

sharply. The first region 12 is therefore less likely to

separate.

[00391

The maximum value of the hardness may be located in

the first region 12. If satisfying this configuration,

the maximum value of the hardness is located in the

vicinity of the surface 11, and it is therefore possible

to increase the hardness of the surface 11 and

neighborhoods thereof.

[0040]

The maximum value of the hardness may be located

closer to a side of the surface 11 than the midportion

12a in the thickness direction A of the first region 12

(refer to FIGs. 1 and 4). If satisfying this

configuration, the maximum value of the hardness is located in the vicinity of the surface 11, and it is therefore possible to increase the hardness of the surface 11 and neighborhoods thereof.

[0041]

The maximum value of the hardness may be located

closer to the surface 11 than the maximum value of

fluorine concentration (refer to FIGs. 3 and 4). If

satisfying this configuration, hardness of a portion

located closer to the surface 11 than a portion having

the maximum value of fluorine concentration becomes

relatively high. A portion located closer to the surface

11 than the portion having the maximum value of fluorine

concentration is less susceptible to damage due to wear

or the like, thereby offering antibacterial activity over

a long period of time.

[00421

The hardness is, for example, 3-10 GPa. The

maximum value of the hardness is, for example, 5-10 GPa.

The hardness is indentation hardness and denotes

deformation resistance of the surface 11 if subjected to

deformation. The hardness is calculated from an

indentation depth when an indenter is pressed against the

surface 11, and power necessary therefor. As a specific

method for measuring hardness, there is, for example,

nanoindentation method (according to ISO 14577).

[0043]

The composite material 1 may further include an oxide film (not illustrated) located on an outermost surface. In this case, the surface 11 of the composite material 1 is composed of a surface of the oxide film. A thickness of the oxide film is, for example, 2-5 nm.

Examples of composition of the oxide film include TiO2

(titanium dioxide). The oxide film may include fluorine.

For example, the oxide film is formed by oxidation

treatment. Examples of oxidation treatment include

natural oxidation, heat treatment, oxygen plasma

treatment, immersion into an oxidation solution, and

anodic oxidation.

[0044]

A content of titanium may be larger than a content

of fluorine in the composite material 1. The composite

material 1 may include titanium as a main composition.

The main composition is a composition whose mass ratio is

highest in the composite material 1.

[0045]

A method for manufacturing a composite material in

one of embodiments is described in detail below by

exemplifying the case of obtaining the above composite

material 1.

[0046]

Firstly, titanium-based metal is prepared. The

titanium-based metal may be washed if necessary. Washing

may be carried out using, for example, an organic solvent.

Examples of the organic solvent include ethanol and

acetone. The organic solvents exemplified here may be

used by being mixed together. The washing may be carried

out while applying ultrasonic waves. The titanium-based

metal after being washed may be subjected to, for example,

vacuum drying in a desiccator.

[0047]

Subsequently, fluorine ions are implanted into a

surface of the titanium-based metal, thereby obtaining

the composite material 1. Examples of implantation

conditions of fluorine ion include the following

conditions.

Implantation energy: more than 30 keV but not more

than 80 keV

Implantation dose: 1x1016 - 5x1017 atom/cm 2

[00481

The obtained composite material 1 may be washed if

necessary. Conditions of the washing may be identical to

those exemplified in the above titanium-based metal. The

composite material 1 after being washed may be subjected

to, for example, vacuum drying in the desiccator.

[0049]

Although the above embodiment has illustrated and

described the case of obtaining the composite material 1

by the fluorine ion implantation, the method for

manufacturing the composite material 1 is not limited

thereto. Other methods other than the fluorine ion implantation are employable as long as the composite material 1 is obtainable.

[0050]

A bioimplant in one of embodiments is described in

detail below with reference to the drawings. As an

example of the bioimplant, a dental implant is described

in the present embodiment.

[0051]

FIG. 2 is a schematic diagram illustrating an

appearance of the dental implant in the embodiment.

[0052]

The dental implant 100 includes a fixture 101, an

abutment 102 attached to an end portion of the fixture

101, and an artificial tooth 103 attached to the fixture

101 with the abutment 102 interposed therebetween.

[0053]

The fixture 101, the abutment 102 and the

artificial tooth 103 in the dental implant 100 include

the composite material 1. Because the composite material

1 has the antimicrobial activity and high hardness as

described earlier, the dental implant 100 is capable of

reducing growth of bacteria and offering excellent

durability against brushing, repetitive use, washing or

the like.

[0054]

For example, the fixture 101, the abutment 102 and the artificial tooth 103 may be individually formed only by the composite material 1. Alternatively, a part of these may be composed by the composite material 1, and the rest may be composed by a material other than the composite material 1. Still alternatively, at least one of the fixture 101, the abutment 102 and the artificial tooth 103 may include the composite material 1, and the rest may include a material other than the composite material 1. This configuration contributes to reducing the growth of bacteria in the surface of the implant.

For example, a reduction in growth of anaerobic bacteria

can be expected because the fixture 101 and the abutment

102 are used in an oxygen-deficient atmosphere. For

example, a reduction in growth of facultative anaerobic

bacteria and aerobic bacteria can be expected because the

artificial tooth 103 is exposed in a buccal cavity and

exposed to air. Thus, the composite material 1 may

suitably be applied to the fixture 101, the abutment 102

and the artificial tooth 103 according to the kind of

bacteria whose growth needs to be reduced, and necessary

antimicrobial performance.

[0055)

The first region 12 in the composite material 1 may

be located at, for example, a portion of the dental

implant 100 with which bacteria is likely to contact and

which is likely to wear out. For example, the dental

implant 100 may be configured so that the first region 12 is located at individual surfaces of the fixture 101, the abutment 102 and the artificial tooth 103. Alternatively, the dental implant 100 may be configured so that the first region 12 is located at individual connection parts of the fixture 101, the abutment 102 and the artificial tooth 103. This is also true for other bioimplant described later and members other than the bioimplant.

[00561

While the embodiments in the present disclosure has

been illustrated and described above, it is to be

understood that the present disclosure is not limited to

the foregoing embodiments and may be made into any

arbitrary ones insofar as they do not depart from the

spirit and scope of the present disclosure.

[0057]

For example, even though the case where the

bioimplant is the dental implant has been described as an

example in the above embodiments, the bioimplant is not

limited thereto. For example, the bioimplant may be an

implant for biocompatible metal, such as titanium.

Examples of other bioimplant include artificial joints

such as femoral stems and acetabulum shells, and spine

surgery implants such as spine fixation instrumentation.

[0058]

Even though the case where the composite material 1

is intended for the bioimplant has been described as an

example in the above embodiments, the composite material

1 is not limited to the purpose of the bioimplant. That

is, the composite material 1 may be used as a material of

a member for which antibacterial activity and high

hardness are necessary. Examples of other members

include orthodontic wire, surgical instrument, hypodermic

needles, glasses frames, tableware, food factory lines,

water bottle faucets, kitchen knives, toilets, Washlet

(registered trademark), taps, and water and sewage pipes.

[00591

The present disclosure is described in detail below

by giving examples. However, the present disclosure is

not limited to the following examples.

EXAMPLES

[0060]

[Examples 1 and 2]

Firstly, the following specimen was prepared.

Specimen: lmm thick pure titanium composed of C. P.

two types titanium

[00611

The above specimen was formed in a disk shape

having a diameter of 14 mm and a thickness of 1 mm. This

was washed with ethanol and acetone while applying

ultrasonic waves, and was then subjected to vacuum drying

in a desiccator. Thereafter, fluorine ions were

implanted into a surface of the specimen under different

conditions, thereby obtaining a composite material 1 of

Example 1 and that of Example 2.

[0062]

Implantation conditions of the fluorine ions were

as follows.

(Example 1)

Implantation energy: 40 keV

Implantation dose: 5x1017 atom/cm 2

(Example 2)

Implantation energy: 40 keV

Implantation dose: 5x10 1 6 atom/cm 2

[0063]

Evaluations were made of the obtained composite

materials 1 after being washed with ethanol and acetone

while applying ultrasonic waves, followed by vacuum

drying in the desiccator.

[00641

[Comparative Example 1]

Comparative Example 1 was the same specimen as

Examples 1 and 2, except that no fluorine ions were

implanted therein.

[0065]

Measurements were made of fluorine concentration,

hardness and crystal structure of the composite materials

1 of Examples 1 and 2. Measurement was also made of

antimicrobial activity of the composite material 1 of

Example 1. Measurements were made of hardness and antimicrobial activity of Comparative Example 1.

[0066]

FIG. 3 is a graph illustrating measurement results

of fluorine concentration in Examples 1 and 2.

[0067]

(Fluorine Concentration)

The fluorine concentrations of Examples 1 and 2

were measured by the XPS and the SIMS. Specifically, a

region where the fluorine concentration is relatively

high and goes beyond a measurement range of the SIMS was

subjected to fluorine concentration calculation by the

XPS, and regions other than the above region was

subjected to fluorine concentration calculation by the

SIMS. Specifically, a range where the fluorine

concentration was less than 10 atom% was subjected to

fluorine concentration calculation by the SIMS. A range

where the fluorine concentration was 10 atom% or more was

subjected to fluorine concentration calculation by the

XPS. The measurement by the XPS was carried out at a

depth of 0-200 nm, and the measurement by the SIMS was

carried out at a depth of 0-900 nm. FIG. 3 illustrates

only the measurement results at the depth of 0-200 nm.

In FIG. 3, the depth 0 nm indicates the surface 11 of the

composite material 1. This is also true for FIG. 4

described later. Measurement conditions for the XPS and

SIMS are as follows.

[0068]

(Measurement Conditions for the XPS)

Analyzer: X-ray Photoelectron Spectroscopy Analyzer

"PHI Quantera II" manufactured by ULVAC-PHI Corporation

X-ray source: Monochrome AlKax

Sputtering ion: Ar+

Accelerating voltage: 4 kV

[0069]

(Measurement Conditions for the SIMS)

Analyzer: Secondary Ion Mass Analyzer "D-SIMS 6650"

manufactured by ULVAC-PHI Corporation

Primary ion species: Cs+

Secondary ion polarity: Negative

Accelerating voltage: 2 kV

Beam current: 25 nA

Charge compensation: None

Raster size: 400 pm

[0070]

Measurement results showed the following. That is,

a maximum value of fluorine concentration was located at

a depth of 90 nm in Example 1. The maximum value of the

fluorine concentration in Example 1 was 63 atom%. A

maximum value of fluorine concentration was located at a

depth of 46 nm in Example 2. The maximum value of the

fluorine concentration in Example 2 was 11 atom%.

[0071]

A region from the depth 0 nm (the surface 11) to a

depth at which the fluorine concentration reached 1 ppm was a region 12, and a thickness T thereof was measured.

The measurement results are as follows.

Thickness T of the first region)

Example 1: 740 nm

Example 2: 390 nm

[0072]

FIG. 4 is a graph illustrating measurement results

of hardness in Examples 1 and 2 and Comparative Example 1.

[0073]

(Hardness)

The hardness was measured by nanoindentation method

(according to ISO 14577). The measurement was carried

out at a depth of 0-1000 nm. FIG. 4 illustrates only the

measurement results at the depth of 0-500 nm.

[0074]

Measurement conditions of hardness are as follows:

Measuring device: "Nanoindenter XP" manufactured by

MTS Systems Corporation

Measuring mode: Continuous stiffness measurement

Indentation depth: Maximum value 1000 nm

Hardness unit: Vickers hardness

[0075]

Measurement results showed the following. That is,

a maximum value of hardness was located at a depth of 70

nm in Example 1, and the maximum value of hardness in

Example 1 was 5 GPa. A maximum value of hardness was

located at a depth of 20 nm in Example 2, and the maximum value of hardness in Example 2 was 7 GPa.

[0076]

(Crystal Structure)

Crystal structure was evaluated by the TEM, XRD and

XPS. In individual measurements of the TEX, XRD and XPS,

the first region 12 was determined from the thickness T

of the first region 12, and a region located more inside

than the first region 12 was a second region.

[0077]

Measurement conditions for the TEM are as follows.

Analyzer: Transmission electron microscope "Talos

F200X" manufactured by FEI Corporation

Accelerating voltage: 200 kV

Beam current value: 150 pA

Measurement location: A cross section of the

composite material 1 being cut out in a thickness

direction

[0078]

Measurement conditions for the XRD are as follows.

Analyzer: "X'Pert PRO-MRD" manufactured by

PANalytical Corporation

Tube: CuKa

Incidence angle: 0.50

Measurement range: 10-120°

[0079]

Measurement conditions for the XPS are the same as

those for the fluorine concentration.

[0080]

Firstly, a cross-section observation by the TEM was

carried out. A diffraction pattern was determined by

referring to data base (TiOF2: ICDD No.00-008-0060,

titanium a-phase: ICDD No.00-044-1294) provided by

International Centre for Diffraction Data, ICDD. As a

result of the observation, a diffraction pattern assigned

to TiOF2 (the crystal phase 2) was obtained in the first

region 12, and a diffraction pattern of titanium c-phase

(the second phase 32) was obtained in the second region

in both Examples 1 and 2.

[0081]

The first phase 31 was observed in the first region

12 in both Examples 1 and 2. A larger number of the

crystal phase 2 than the first phase 31 were observed in

Example 1. A larger number of the first phases 31 than

the crystal phase 2 were observed in Example 2. The

amorphous phase 4 and the mixed phase 5 were observed in

the first region 12 in Example 1.

[0082]

Then, measurement by the XRD was carried out. A

diffraction pattern was determined by referring to the

JCPDS provided by ICDD. As a result of the measurement,

a crystal structure different from that of the second

region was observed in the first region 12.

[0083]

Subsequently, measurement by the XPS was carried out. Peak assignment is presented in Table 1. As a result of the measurement, peaks assigned to TiF3, TiF4 and F-TiO2 were obtained in both Examples 1 and 2.

Although a peak assigned to Ti-F-Ti bonding was obtained,

the peak seems to be caused by a crystal of titanium

fluoride. In other respect, states illustrated in FIG. 1

were confirmed.

[0084]

C14 a)

C0 0 a

0C

4i

0

C..J4

C 1 . CJ C -4 CD C' ('~C)m 4J a') C, -r-.l) -CV) C c E -0 - 9 c'4 = 0.0a) < 0

Ca -C. 40 >0 0 > o

0U5 0 4)J- w 0 (U/ (

CC (U (tU (0 4) 4 )J _

4) -'4-0

0o E ~ E :3 E -0

m .9 co5 U2cC 0L) (D 2 L I 4) i C L d -:L C _ pc ' R 0

(U L

-l) cC% m'~ m

:3,0 0.0

r129

[0085]

(Antibacterial Activity)

Antibacterial activity was measured by a film

adhesion test using staph aureus (according to JIS Z

2801).

[0086]

Measurements results were as follows.

Attached viable cell count (CFUs)

Example 1: <10 (detection limit or less)

Comparative Example 1: 17667

[0087]

As a result of the measurement, the attached viable

cell count was the detection limit or less in Example 1.

Antibacterial activity value of Example 1 was 3.2.

Consequently, it became apparent that Example 1 had

antibacterial effect.

DESCRIPTION OF THE REFERENCE NUMERAL

[0088]

1 composite material

2 crystal phase of titanium fluoride

3 metal crystal phase of titanium

31 first phase

32 second phase

4 amorphous phase

5 mixed phase

11 surface

12 first region

12a midportion

T thickness

A thickness direction

13 second region

100 dental implant

101 fixture

102 abutment

103 artificial tooth

Claims

CLAIMS:

1. A composite material, comprising: a crystal phase of titanium fluoride; an amorphous phase comprising titanium and fluorine; and a metal crystal phase of titanium, the crystal phase of the titanium fluoride being present in a first region located away from a surface in a depth direction.

2. The composite material according to claim 1, wherein the titanium fluoride is TiOF2.

3. The composite material according to claim 1 or claim 2, wherein the metal crystal phase comprises a first phase comprising fluorine.

4. The composite material according to claim 3, wherein the first phase is located in the first region.

5. The composite material according to claim 3 or claim 4, wherein: the metal crystal phase further comprises a second phase located more inside than the first phase, and the second phase comprises no fluorine.

6. The composite material according to claim 5, wherein the second phase is located more inside than the first region.

7. The composite material according to any one of claims I to 6, further comprising: a mixed phase comprising: the amorphous phase, the crystal phase of the titanium fluoride, and the metal crystal phase.

8. The composite material according to any one of claims 1 to 7, wherein a fluorine concentration reaches a maximum value at a portion located more inside than the surface.

9. The composite material according to claim 8, wherein the fluorine concentration increases to the maximum value when going from the surface toward inside.

10. The composite material according to claim 8 or claim 9, wherein the fluorine concentration reaches the maximum value in the first region.

11. The composite material according to claim 10, wherein the fluorine concentration reaches the maximum value at a side closer to the surface than a midportion in a depth direction of the first region.

12. The composite material according to any one of claims 1 to 11, wherein hardness reaches a maximum value at a portion located more inside than the surface.

13. The composite material according to claim 12, wherein the hardness increases to the maximum value when going from the surface toward inside.

14. The composite material according to claim 12 or claim 13, wherein the hardness reaches the maximum value in the first region.

15. The composite material according to claim 14, wherein the hardness reaches the maximum value at a side closer to the surface than a midportion in a depth direction of the first region.

16. The composite material according to any one of claims I to 15, wherein hardness reaches a maximum value at a side closer to the surface than a position at which a fluorine concentration reaches a maximum value.

17. The composite material according to any one of claims 1 to 16, the composite material being intended for a bioimplant.

18. A bioimplant comprising the composite material according to any one of claims I to 17.

19. The bioimplant of claim 18, wherein the implant is: a dental implant, an artificial joint, or a spine surgery implant.